1. Field of the Invention
The invention pertains to air conditioning unit constructions and in particular to constructions involving refrigerant coil dispositions and cabinet constructions to accommodate different positionings of the unit.
2. Description of the Prior Art
The general type of air conditioning unit with which this invention is mainly concerned is sometimes called an air handler in the art, and basically includes a cabinet having a refrigerant evaporator coil in what is called the coil section, and a blower in the adjacent blower section. Such units are ordinarily used in what is called a split system where the refrigerant compressor and condenser are housed in a separate remote unit.
Depending upon the particular building construction in which the unit is to be installed, it is desirable that a given unit be adapted for installation in either a vertical disposition or a horizontal disposition. Further, in the vertical disposition the application may be for either up-flow in which the air passes upwardly through the unit, or in down-flow in which the air passes down through the unit. It is also desirable in the vertical dispositions that the air inlet location be available not only at the end of the unit, but alternatively at least from one side of the coil section. Thus in a vertical disposition, it is necessary that condensate be able to be connected at whichever edge of the coil is lower, and in the horizontal disposition, provision should be made to not only collect condensate at the lower edge of the coil, but also to catch condensate which may drip from the fins and pass it to the drain trough at the lower edge of the coil.
Different manufacturers typically have different approaches to solving the problem of providing for the various dispositions of the cabinet, as well as collecting the condensate regardless of disposition and regardless of the direction of entering air flow. In some cases, the coil is arranged to be removed and repositioned, and sometimes with a repositioning of whatever condensate drain trough is used. One disadvantage of such arrangement is that typically the access panels which are removed for accomplishing the rearrangement must be provided with knockouts to accommodate drain outlets and refrigerant line connections in the various locations where they fall in accordance with coil positioning. Additionally, patch plates may be required to be used and sometimes the knockout openings, particularly if slotted, are not especially easy to seal. One example of prior art in which a number of knockouts are provided may be found in U.S. patent application Ser. No. 829,701, filed Sept. 1, 1977.
Another disadvantage of the multiple knockout approach is that the panels containing the knockouts are weakened as contrasted with a panel of the same gauge without knockouts. Thus additional stiffening members may be required where the knockout panels are lacking in the requisite rigidity and strength.
The reason for providing some flexibility in disposition of the cabinet and the coils is of course to avoid requiring a manufacturer of units to make a different model to accommodate each particular installation. The problem of making different models is compounded by the significant number of different capacity air handler units required for different installations.
The problem of cabinet and coil dispositions has been recognized in the air conditioning field and the following examples are representative of U.S. patents dealing with the subject: U.S. Pat. Nos. 3,089,315; 3,299,660; 3,596,475; and 3,678,993.
The basic approach of my invention is to provide a cabinet and coil assembly in which the coil remains in its disposition irrespective of whether the cabinet is to be installed in an upright, inverted, or horizontal disposition. To accommodate the inverted disposition, an auxiliary drain trough is added as an accessory without removing the coil. For the horizontal disposition, a drip pan is added to underlie the area in a horizontal plane below the downstream face of the coil. The invention also provides a cabinet which is constructed to cooperate with the projecting elements such as drain outlets and refrigerant line connections to aid in holding the coil in place in the cabinet, but with these projections occurring in parts of the front wall of the cabinet which are more of a structural character than of an access character so that the access panels may be devoid of knockouts.